Pauci-immune Glomerulonephritis Research Articles

A case of (double) ANCA-negative granulomatosis with polyangiitis (Wegener's).

A 60-year-old man had experienced cough, bloody sputum, and a 38°C fever for 1.5months. He visited an outpatient clinic and received antibiotics and nonsteroidal anti-inflammatory drugs. However, because the symptoms continued, he visited our hospital. The past medical history included chronic sinusitis, hypertension, and diabetes mellitus. A chest x-ray film and computed tomography showed multiple pulmonary nodules with cavities. Macrohematuria had developed 3days before admission, and renal function had deteriorated (creatinine, 2.45mg/dL) in 2weeks. He was admitted to our hospital because of rapidly progressive glomerulonephritis (RPGN) and multiple pulmonary nodules. On admission, the clinical diagnosis was suspected to be granulomatosis with polyangiitis (Wegener's) (GPA), although tests for proteinase-3 anti-neutrophil cytoplasmic antibody (PR3-ANCA) were negative. Antibiotics were administered for 5days. After renal biopsy, methylprednisolone pulse therapy and cyclophosphamide pulse therapy were performed. The pathological diagnosis on the basis of the renal biopsy was glomerular and interstitial hemorrhage, possibly associated with vasculitis. After the treatment, the pulmonary symptoms, multiple pulmonary nodules, and severe inflammatory reactions in the peripheral blood were resolved. However, renal dysfunction progressed to end-stage renal disease 1month after renal biopsy. Hemodialysis was started, and the steroid therapy was continued. During hemodialysis, a second renal biopsy was performed and led to a diagnosis of pauci-immune focal segmental crescentic glomerulonephritis. Renal function gradually recovered, and hemodialysis was discontinued. This case was (double) ANCA-negative GPA which presented prominent glomerular and interstitial hemorrhage, may be associated with small vessel vasculitis, but without active necrotizing and crescentic glomerular lesions, in the rapidly progressive glomerulonephritis.

Persistent or New Onset Microscopic Hematuria in Patients with Small Vessel Vasculitis in Remission: Findings on Renal Biopsy

Hematuria is considered a sign of active renal disease in patients with small-vessel vasculitis. In patients who are in apparent clinical remission, presence of persistent or new-onset microscopic hematuria may reflect active vasculitis, damage, or other glomerular pathology. We identified 74 patients from the Johns Hopkins Renal Pathology database between 1995 and 2009 with the diagnosis of pauciimmune glomerulonephritis (GN). Among them we identified 9 who were in clinical remission and underwent a renal biopsy for evaluation of persistent or new-onset hematuria. Nine patients with small-vessel vasculitis, 8 antineutrophil cytoplasmic antibody (ANCA)-positive and 1 ANCA-negative, underwent a renal biopsy at variable time periods after remission of vasculitis (6 to 164 months) for persistent microscopic hematuria (n = 6) or new-onset microscopic hematuria (n = 3). All patients were in apparent clinical remission at the time of renal biopsy. Of the 3 patients presenting with new-onset hematuria, 2 had crescentic IgA nephropathy and 1 had healed crescentic pauciimmune GN. Of the 6 patients with persistent hematuria, 2 had arteriosclerosis, 2 had focal segmental glomerulosclerosis, and 2 had global and segmental glomerulosclerosis and healed crescentic GN, and none had active vasculitis. Microscopic hematuria in patients with renal vasculitis otherwise in remission could represent chronic glomerular injury from prior episode of vasculitis or may represent new glomerular pathology. Renal biopsy should be considered in these patients to guide therapy.

Pauci-immune crescentic glomerulonephritis in limited cutaneous systemic sclerosis

Pauci-immune necrotizing glomerulonephritis is a form of a rapidly progressive glomerulonephritis that is associated with the anti-neutrophil cytoplasmic antibodies (ANCA). ANCA-associated pauci-immune glomerulonephritis may be secondary to rheumatic diseases. We report on a patient with limited cutaneous systemic sclerosis who presented with subacute onset of nephritic syndrome and renal insufficiency. Her myeloperioxidase ANCA titer was elevated and renal biopsy confirmed pauci-immune crescentic glomerulonephritis, which was stabilized with high-dose glucocorticoid and cyclophosphamide. ANCA-associated necrotizing glomerulonephritis is rarely reported in systemic sclerosis and a systematic review is presented.

Increased Sensitivity of the European Medicines Agency Algorithm for Classification of Childhood Granulomatosis with Polyangiitis

Granulomatosis with polyangiitis (Wegener's; GPA) and other antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) are rare in childhood and are sometimes difficult to discriminate. We compared use of adult-derived classification schemes for GPA against validated pediatric criteria in the ARChiVe (A Registry for Childhood Vasculitis e-entry) cohort, a Childhood Arthritis and Rheumatology Research Alliance initiative. Time-of-diagnosis data for children with physician (MD) diagnosis of AAV and unclassified vasculitis (UCV) from 33 US/Canadian centers were analyzed. The European Medicines Agency (EMA) classification algorithm and European League Against Rheumatism/Paediatric Rheumatology International Trials Organisation/Paediatric Rheumatology European Society (EULAR/PRINTO/PRES) and American College of Rheumatology (ACR) criteria for GPA were applied to all patients. Sensitivity and specificity were calculated (MD-diagnosis as reference). MD-diagnoses for 155 children were 100 GPA, 25 microscopic polyangiitis (MPA), 6 ANCA-positive pauciimmune glomerulonephritis, 3 Churg-Strauss syndrome, and 21 UCV. Of these, 114 had GPA as defined by EMA, 98 by EULAR/PRINTO/PRES, and 87 by ACR. Fourteen patients were identified as GPA by EULAR/PRINTO/PRES but not by ACR; 3 were identified as GPA by ACR but not EULAR/PRINTO/PRES. Using the EMA algorithm, 135 (87%) children were classifiable. The sensitivity of the EMA algorithm, the EULAR/PRINTO/PRES, and ACR criteria for classifying GPA was 90%, 77%, and 69%, respectively, with specificities of 56%, 62%, and 67%. The relatively poor sensitivity of the 2 criteria related to their inability to discriminate patients with MPA. EULAR/PRINTO/PRES was more sensitive than ACR criteria in classifying pediatric GPA. Neither classification system has criteria for MPA; therefore usefulness in discriminating patients in ARChiVe was limited. Even when using the most sensitive EMA algorithm, many children remained unclassified.

Recurrence of anti‐neutrophil cytoplasmic antibody vasculitis in the kidney allograft

We report a case of recurrent anti-cytoplasmic neutrophil antibody (ANCA)-associated vasculitis post kidney transplantation. A 60-year-old woman underwent uncomplicated deceased-donor kidney transplantation for end-stage renal disease (ESRD) secondary to myeloperoxidase-specific ANCA-associated vasculitis, after six years of haemodialysis, and clinical remission. Immunosuppression was with tacrolimus/mycophenolate and prednisolone after basiliximab induction therapy. Five weeks post-transplantation, an allograft biopsy, done for a rising creatinine and glomerular haematuria, revealed pauci-immune crescentic glomerulonephritis. This was treated with pulse methylprednisolone, increase in maintenance prednisolone, 7 sessions of plasma exchange, and replacement of mycophenolate with cyclophosphamide. Tacrolimus was continued throughout. After 3 months of therapy a repeat allograft biopsy showed quiescent vasculitis. The cyclophosphamide was then ceased, and mycophenolate reinstituted. The patient has maintained clinical and histological stability. Reported rates of ANCA-associated vasculitis recurrence post-kidney transplantation have varied but are low compared with other types of glomerulonephritis and seemed to have further declined in the era of modern immunosuppression. Given the low recurrence rate and excellent outcomes in suitable patients, kidney transplantation remains the optimal form of renal replacement therapy for ESRD due to ANCA-associated vasculitis. Whilst re-introduction of cyclophosphamide has been the mainstay of therapy, additional reported successful therapeutic strategies have included pulse methylprednisolone, plasma exchange and rituximab. Further study on the most effective and safest treatment options would be of use given the current paucity of data in this area.

Increasing Incidence in PAUCI-Immune Glomerulonephritis in a Community Hospital

Increasing Incidence in PAUCI-Immune Glomerulonephritis in a Community Hospital

Granulomatosis with Polyangiitis in Childhood

Granulomatosis with polyangiitis (GPA) is a rare yet frequently organ- or life-threatening systemic vasculitis affecting small- to medium-sized arteries in multiple organs. It characteristically leads to alveolar hemorrhage and destructive, pauci-immune glomerulonephritis. GPA is also characterized by granulomas in the upper and lower respiratory tract causing erosive sinusitis and nodular or even cavitating lesions in the respiratory tract. Antineutrophil cytoplasmic antibodies, a hallmark of GPA, are likely integral to the pathogenesis and recently have become a therapeutic target. International collaborations in childhood vasculitis have led to the development and validation of childhood vasculitis classification criteria,advanced our understanding of the clinical phenotype at presentation of GPA, and improved our ability to capture disease activity and determine treatment choices. Treatment efficacy and safety data continue to be largely derived from adult GPA studies. This review focuses on the recent publications on epidemiology, pathogenesis, and treatment in childhood GPA and relevant publications from the adult GPA literature.

AA-amyloidosis in a kidney biopsy on top of pauci-immune crescentic glomerulonephritis.

In March 2011, a 56-year-old woman presented with fever of unknown origin accompanied with symmetric arthralgias and sinusitis. Her medical history was notable for diabetes mellitus Type 2, hypertension, smoking and multiple episodes of sinusitis. Admission blood chemistry tests revealed a leucocyte count of 14.3 × 109/L, a C-reactive protein (CRP) level of 4.4 mg/dL (<0.5 mg/dL), a creatinine level of 266.6 μmol/L and a blood urea nitrogen (BUN) level of 47 mg/dL. Urinalysis demonstrated gross proteinuria with a total protein/creatinine ratio of 6.4 g/g and nephritic sediment. Anti-nuclear, anti-GBM and MPO-ANCA antibodies were negative, Complement factor 3 and 4 in the normal range but PR3-ANCA antibodies were clearly detectable. Of note, computed tomography of her head and thorax displayed signs of pansinusitis but no pulmonary changes. A kidney biopsy was performed which revealed pauci-immune crescentic glomerulonephritis with crescent formation in 9 of 14 glomeruli. Most interestingly, glomeruli demonstrated Periodic Acid Schiff (PAS)-negative mesangial and perihilar deposits (Figure 1), which were positive for congo red (Figure 2, upper left insert). Immunohistochemistry revealed positivity for amyloid-P and amyloid-A (Figure 2, lower right insert). Electron microscopy confirmed fibrillary deposits consistent with amyloid (Figure 2). Amyloid was also present in arteriolar walls in the kidney. Since all other causes of AA-amyloidosis were excluded, the most probable underlying cause for AA-amyloidosis in our patient is long lasting granulomatosis with polyangiitis (Wegener’s). Since our patient suffered from multiple episodes of sinusitis in her medical history, it might be speculated that granulomatosis with polyangiitis (Wegener’s) was long-lasting, allowing the development of AA-amyloidosis. Fig. 1. A cellular crescent and PAS-negative perihilar and mesangial amyloid deposits (arrows) are present within one and the same glomerulum (PAS stain). Fig. 2. Typical fibrillary structure of amyloid deposits on transmission electron microscopy (uranyl acetate and lead citrate). Upper left inset: positive congo red staining of amyloid deposits. Lower right inset: positive immunohistochemistry for Amyloid A. Treatment of the patient was started with corticosteroids and intravenous cyclophosphamide. Because of a further decrease of kidney function requiring haemodialysis treatment, plasmapheresis was performed. After daily intensive plasmapheresis treatment for >2 weeks PR3-ANCAs became negative and fever as well as arthralgias resolved, but the patient’s kidney function has not recovered as yet.

Diffuse tubulointerstitial nephritis associated with ANCA-negative pauci-immune glomerulonephritis

Tubulointerstitial nephritis (TIN) is histopathologically characterized by the infiltration of leukocytes, edema, and fibrosis of the renal interstitium with or without tubulitis and vasculitis. TIN is not usually accompanied by specific glomerular lesions. We herein report the case of a 65-year-old male with a diagnosis of non-small cell lung carcinoma that showed acute renal failure, together with proteinuria and microscopic hematuria. The renal biopsy findings showed severe and diffuse TIN, despite the fact that glomerulonephritis (GN) with cellular crescents was only focally identified. In this case, the GN was of the pauci-immune type, but the serum tests for anti-neutrophil cytoplasmic antibodies were negative. No disorders known to be associated with TIN were detected. The pathogenesis involved in this unusual presentation of a concomitant occurrence of TIN and pauci-immune GN is currently unclear.

Le rein transplanté : une cible des maladies systémiques

Recurrence of disease after transplantation is frequent and represents the third cause of allograft loss. Recurrence of lupus nephritis after transplantation is rare. Kidney transplantation in patients with antiphospholipid syndrome or lupus anticoagulant is challenging due to the high risk of immediate post-transplant thrombosis and bleeding risk associated to the subsequent anticoagulation. Moreover, vascular changes associated to the presence of antiphospholipid antibodies negatively impact allograft rate survival. Recurrence of pauci immune glomerulonephritis or Goodpasture syndrome is exceptional.

Anti-Proteinase 3 Anti-Neutrophil Cytoplasm Autoantibodies Recapitulate Systemic Vasculitis in Mice with a Humanized Immune System

Evidence is lacking for direct pathogenicity of human anti-proteinase-3 (PR3) antibodies in development of systemic vasculitis and granulomatosis with polyangiitis (GPA, Wegener's granulomatosis). Progress in study of these antibodies in rodents has been hampered by lack of PR3 expression on murine neutrophils, and by different Fc-receptor affinities for IgG across species. Therefore, we tested whether human anti-PR3 antibodies can induce acute vasculitis in mice with a human immune system. Chimeric mice were generated by injecting human haematopoietic stem cells into irradiated NOD-scid-IL2Rγ−/− mice. Matched chimera mice were treated with human IgG from patients with: anti-PR3 positive renal and lung vasculitis; patients with non-vasculitic renal disease; or healthy controls. Six-days later, 39% of anti-PR3 treated mice had haematuria, compared with none of controls. There was punctate bleeding on the surface of lungs of anti-PR3 treated animals, with histological evidence of vasculitis and haemorrhage. Anti-PR3 treated mice had mild pauci-immune proliferative glomerulonephritis, with infiltration of human and mouse leukocytes. In 3 mice (17%) more severe glomerular injury was present. There were no glomerular changes in controls. Human IgG from patients with anti-PR3 autoantibodies is therefore pathogenic. This model of anti-PR3 antibody-mediated vasculitis may be useful in dissecting mechanisms of microvascular injury.

Pulmonary Hemorrhage and Renal Involvement in Benzylthiouracil- Induced Vasculitis

Abstract Introduction: Vasculitis is a rare complication of antithyroid drugs reported with propylthiouracil, carbimazole, methimazole and Benzylthiouracil. Benzylthiouracil –induced Vasculitis are often severe forms with renal or pulmonary involvement, which can be life-threatening if left untreated .We describe the clinical course and medical management of 2 cases of severe vasculitis with alveolar hemorrhage and renal involvement occurred in 2 patients with Graves’ disease treated by Benzylthiouracil . Cases report: A 36 and 33-year-old women with Graves’ disease developed alveolar hemorrhage and acute renal failure after respectively 36 and 144 months of Benzylthiouracil therapy. Kidney biopsy showed pauci-immune crescentic glomerulonephritis in the 2 cases. Anti Neutrophil Cytoplasmic Antibody (ANCA) was positive (P- ANCA in the first patient and c-ANCA in the second patient). The condition of the first patient improved when Benzylthiouracil was withdrawn associated with corticosteroids and immunosuppressive treatment after a follow up of 6 months. However, the second patient died by severe infection after the same treatment. Conclusion: Benzylthiouracil vasculitis is a serious complication but its prognosis is good if diagnosis and treatment are early. However mortality is related to risk of infection.

A Case of Rifampin-Induced Crescentic Glomerulonephritis

A 56-year-old male with pulmonary tuberculosis was admitted to our hospital for evaluation of generalized edema. He began antituberculosis treatment with rifampin, isoniazid, ethambutol, and pyrazinamide. He experienced abnormal increments in weight and serum creatinine after 6 weeks. All serological findings, including anti-neutrophil cytoplasmic antibodies (ANCA), were negative. Rifampin was stopped because it might have caused the increase in creatinine. Renal biopsy was consistent with pauci-immune crescentic glomerulonephritis (CrGN). His renal function was improved by high-dose steroid treatment. Rifampin-induced, ANCA-negative pauci-immune CrGN is very rare; most cases of rifampin-induced acute renal failure are due to acute tubulointerstitial nephritis. We present here a case of rifampin-induced CrGN and pulmonary tuberculosis successfully treated with high-dose steroids and antituberculosis medications, excluding rifampin. (Korean J Med 2012;82:236-240)

Familial Non Medullary Thyroid Cancer: Clinic Cases and Review of literature

Abstract Introduction: Vasculitis is a rare complication of antithyroid drugs reported with propylthiouracil, carbimazole, methimazole and Benzylthiouracil. Benzylthiouracil –induced Vasculitis are often severe forms with renal or pulmonary involvement, which can be life-threatening if left untreated. We describe the clinical course and medical management of 2 cases of severe vasculitis with alveolar hemorrhage and renal involvement occurred in 2 patients with Graves’ disease treated by Benzylthiouracil . Cases report: A 36 and 33-year-old women with Graves’ disease developed alveolar hemorrhage and acute renal failure after respectively 36 and 144 months of Benzylthiouracil therapy. Kidney biopsy showed pauci-immune crescentic glomerulonephritis in the 2 cases. Anti Neutrophil Cytoplasmic Antibody (ANCA) was positive (P- ANCA in the first patient and c-ANCA in the second patient). The condition of the first patient improved when Benzylthiouracil was withdrawn associated with corticosteroids and immunosuppressive treatment after a follow up of 6 months. However, the second patient died by severe infection after the same treatment. Conclusion: Benzylthiouracil vasculitis is a serious complication but its prognosis is good if diagnosis and treatment are early. However mortality is related to risk of infection.

Clinical and Histological Outcome Predictors in Renal Limited Pauci-Immune Crescentic Glomerulonephritis: A Single Centre Experience

Renal-limited vasculitis is a pauci-immune crescentic glomerulonephritis with no signs of systemic involvement, representing one of the most common causes of rapidly progressive glomerulonephritis. The study aims to examine clinical and histological features in twenty-four patients with RLV diagnosed by the Nephrology Department of Sapienza University of Rome, Italy, evaluating the role of these parameters in predicting renal survival. Patients details, clinical and histological features and outcomes were recorded at the time of renal biopsy and over a mean follow-up period of 36±6 months. In our study, serum creatinine at presentation was significantly higher in patients who had a poor outcome than in those who survived with independent renal function (6.3±2.47 mg/dl vs 2.84±2.01 mg/dl, P= 0.002). The presence of C3c was found in the area of glomerular fibrinoid necrosis and in small arteries and arterioles with fibrinoid necrosis in 17 patients (P= 0.018). In conclusion, serum creatinine at presentation and focal C3c depositions in areas of glomerular and arteriolar fibrinoid necrosis were the best determinants of poor renal outcome, maybe underlining the pathogenic role of alternative pathway activation of complement system but also demonstrating the focal distribution of necrotizing lesions.

Renal histology in pauci-immune rapidly progressive glomerulonephritis: 8-year retrospective study

The need to perform reporting of renal biopsies of antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitides in a more uniform manner required relook at our eight-year data. To document detailed renal histopathology of pauci-immune rapidly progressive glomerulonephritis (RPGN) and also to seek any significant differences in renal histology of C-ANCA-positive, P-ANCA-positive, and ANCA-negative patients. A detailed analysis of the histopathologic features of renal biopsies of 48 patients in whom a diagnosis of pauci-immune glomerulonephritis was concluded on renal biopsy and who presented clinically as rapidly progressive renal failure was done. One-way ANOVA and Pearson Chi square tests. Compared with ANCA +ve patients, the ANCA -ve patients were much younger (46.85 ± 16.12 years vs 34.28±15.94 years). No significant differences were found between renal lesions of C-ANCA, P-ANCA, and ANCA-negative patients, except for diffuse tubular atrophy which was more severe and more frequently present with P-ANCA positivity (P value=0.013). Pauci-immune RPGN (irrespective of ANCA status) is a relatively rare disorder in patients who are undergoing the renal biopsy at our institute, constituting 2% of all renal biopsies submitted. It is mandatory to have ANCA serology status during reporting of a kidney biopsy showing pauci-immune crescentic or necrotizing glomerulonephritis. Also, if a uniform reporting strategy is followed throughout the country, the studies from this vast country will be comparable.

Late-onset cystoid macular edema as a presenting symptom of anca-negative pauciimmune crescentic glomerulonephritis.

The purpose of this study was to report the appearance of late-onset cystoid macular edema (CME) as an initial manifestation of antineutrophil cytoplasmic antibody-negative pauciimmune glomerulonephritis. Optical coherence tomography was obtained on a female patient after presentation of CME after cataract surgery in the right eye. Follow-up optical coherence tomographies were obtained after resolution of symptoms and on development and resolution of CME in the fellow eye. The patient developed unilateral CME 6 months after uncomplicated cataract surgery and after a seizure was diagnosed with antineutrophil cytoplasmic antibody-negative pauciimmune glomerulonephritis. The CME resolved within 2 months of initiating topical nonsteroidal antiinflammatory drug and steroid treatment. Several months later, after undergoing uncomplicated cataract surgery in the fellow eye, the patient developed CME 4 weeks after surgery despite topical nonsteroidal antiinflammatory drug and steroid prophylaxis. The CME quickly resolved with topical treatment, and there has been no recurrent CME in either eye. Review of the literature shows a potential shared mechanism of CME and antineutrophil cytoplasmic antibody-negative pauciimmune glomerulonephritis. These findings demonstrate a potential association between CME and antineutrophil cytoplasmic antibody-negative pauciimmune glomerulonephritis. Patients with this form of glomerulonephritis may benefit from pre- and postoperative topical antiinflammatory prophylaxis.

Orbital pseudotumor: A single precursor clinical manifestation of Wegener granulomatosis in a ten year old boy

Wegener granulomatosis (WG) is a type of vasculitis characterized by the presence of anti-neutrophil cy-toplasmic antibodies (ANCA) and inflammation of small and medium sized vessels with granulomas formation. Most commonly affected organs include upper and lower respiratory tract, kidneys, eyes, nervous system and skin. Kidneys’ involvement has a central position in the classification, diagnosis, treatment and prognosis of patients with WG, and is characterized by the presence of necrotic glomerulonephritis and clinical manifestations that vary from microscopic hematuria to acute renal insufficiency. We describe a case report of a ten year old boy presenting with microscopic hematuria of glomerular origin and a medical history of orbital pseudotumor two years before his hospitalization due to renal symptoms. Renal biopsy revealed lesions of pauci-immune glome-rulonephritis and findings of granulomatous inflam-mation and necrotizing vasculitis. Serum was positive for p-ANCA antibodies (perinuclear staining pattern ANCA antibodies). These findings led to the diagnosis of WG of generalized form (according to EULAR/ PRINTO/PRES criteria). The patient has been treated with aggressive immunotherapy with the use of ster-oids, cyclophosphamide and mycophenolate mofetil. Disease remission has been established and retained one year after initial diagnosis. Orbital pseudotumor, which is a diagnosis of exclusion, has been the initial disease’s clinical manifestation, even though at that time neither the ocular biopsy nor the immunologic workup had been indicative in terms of WG. Although WG is very rare in children, this disease should always been included in the differential diagnosis in patients with similar clinical manifestations and clinicians should emphasize on the recognition of granulomatous vasculitis in biopsies as well as on repeated tests for ANCA antibodies’ detection in serum. High morbidity and mortality rates [1] of this clinical entity necessitates the early recognition of atypical disease’s forms and the close follow up in cases of uncertain initial diagnosis.

Shedding new light on vasculitis: how the LAMP story unfolded

The last couple of years have brought some major advances both in our understanding of antineutrophil cytoplasmic antibody (ANCA)-positive vasculitis pathogenesis mechanisms and in its treatment options. Recent discoveries of completely new antigens such as lysosome-associated membrane protein-2 (LAMP-2) have meant a huge step forward, and the fact that this antigen is homologous to proteins of bacterial fimbria caused a shift in the focus regarding underlying pathomechanisms of ANCA vasculitis toward bacterial infections, mainly with Klebsiella or Escherichia species, possibly playing a role in triggering the disease. So nephrology has seen real progress in understanding of glomerulonephritis disease mechanisms - not only regarding primary membranous glomerulonephritis (with the recent identification of the phospholipase A2 receptor being the underlying antigen) but also regarding secondary pauci-immune glomerulonephritis due to ANCA-positive vasculitis.

Membranous Nephropathy with Crescents

Membranous nephropathy is a common cause of nephrotic syndrome in adults and can be primary or secondary to systemic lupus erythematosus, chronic infection, or drugs. Rapid decline in renal function in patients with membranous nephropathy may be due to renal vein thrombosis, malignant hypertension, or an additional superimposed destructive process involving the renal parenchyma. Crescents are rare in primary membranous nephropathy and thus suggest another underlying disease process, such as combined membranous and focal or diffuse lupus nephritis. However, in some patients with membranous nephropathy and crescents, the crescentic lesion may be due to a distinct, separate disease process, such as anti-glomerular basement membrane antibodies or anti-neutrophil cytoplasmic antibodies-related pauci-immune glomerulonephritis. Here we describe a case with such renal biopsy findings, review previous reported cases, and discuss possible implications for pathogenesis of the coexistence of these lesions.